High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S

• Published in: Physical review letters 2024-11, Vol.133 (22), p.221001, Article 221001
• Main Authors: Aharonian, F, Benkhali, F Ait, Aschersleben, J, Ashkar, H, Backes, M, Martins, V Barbosa, Batzofin, R, Becherini, Y, Berge, D, Bernlöhr, K, Bi, B, Böttcher, M, Boisson, C, Bolmont, J, de Lavergne, M de Bony, Borowska, J, Bouyahiaoui, M, Brose, R, Brown, A, Brun, F, Bruno, B, Bulik, T, Burger-Scheidlin, C, Bylund, T, Casanova, S, Celic, J, Cerruti, M, Chand, T, Chandra, S, Chen, A, Chibueze, J, Chibueze, O, Collins, T, Cotter, G, Mbarubucyeye, J Damascene, Devin, J, Djuvsland, J, Dmytriiev, A, Egberts, K, Einecke, S, Ernenwein, J-P, Fegan, S, Feijen, K, Fontaine, G, Funk, S, Gabici, S, Gallant, Y A, Glicenstein, J F, Glombitza, J, Grolleron, G, Heß, B, Hofmann, W, Holch, T L, Holler, M, Horns, D, Huang, Zhiqiu, Jamrozy, M, Jankowsky, F, Joshi, V, Jung-Richardt, I, Kasai, E, Katarzyński, K, Kerszberg, D, Khatoon, R, Khélifi, B, Kluźniak, W, Komin, Nu, Kosack, K, Kostunin, D, Kundu, A, Lang, R G, Le Stum, S, Leitl, F, Lemière, A, Lemoine-Goumard, M, Lenain, J-P, Leuschner, F, Luashvili, A, Mackey, J, Malyshev, D, Marandon, V, Marinos, P, Martí-Devesa, G, Marx, R, Meyer, M, Mitchell, A, Moderski, R, Moghadam, M O, Mohrmann, L, Montanari, A, Moulin, E, de Naurois, M, Niemiec, J, Ohm, S, Olivera-Nieto, L, Wilhelmi, E de Ona, Ostrowski, M, Panny, S, Panter, M
• Format: Article
• Language: English
• ISSN: 0031-9007; 1079-7114; 1079-7114
• DOI: 10.1103/PhysRevLett.133.221001

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System, covering 2 orders of magnitude in energy and reaching a proton rejection power of better than 10^{4}. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from Γ_{1}=3.25±0.02(stat)±0.2(sys) to Γ_{2}=4.49±0.04(stat)±0.2(sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms.